glibc/sysdeps/unix
Lukasz Majewski 177a3d48a1 y2038: linux: Provide __clock_getres64 implementation
This patch provides new __clock_getres64 explicit 64 bit function for
getting the resolution (precision) of specified clock ID. Moreover, a
32 bit version - __clock_getres has been refactored to internally use
__clock_getres64.

The __clock_getres is now supposed to be used on systems still supporting
32 bit time (__TIMESIZE != 64) - hence the necessary conversion from 64 bit
struct __timespec64 to struct timespec.

The new clock_getres_time64 syscall available from Linux 5.1+ has been used,
when applicable.
On systems which are not supporting clock_getres_time64 (as their
clock_getres supports 64 bit time ABI) the vDSO syscall is attempted.
On the contrary the non-vDSO syscall is used for clock_getres_time64 as
up till now the kernel is not providing such interface.

No additional checks (i.e. if tv_nsec value overflow) are performed on
values returned via clock_getres{_time64} syscall, as it is assumed that
the Linux kernel will either return 0 and provide correct value or error.

The check for tv_sec being out of range on systems still supporting 32 bit
time (__TIMESIZE != 64) without Y2038 time support is also omitted as it is
_very_ unlikely that we would have a timer with resolution which exceeds 32
bit time_t range.

Build tests:
- The code has been tested on x86_64/x86 (native compilation):
make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8"

- The glibc has been build tested (make PARALLELMFLAGS="-j8") for
x86 (i386), x86_64-x32, and armv7

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

- Use of cross-test-ssh.sh for ARM (armv7):
  make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck

Linux kernel, headers and minimal kernel version for glibc build test
matrix:
- Linux v5.1 (with clock_getres_time64) and glibc build with v5.1 as
  minimal kernel version (--enable-kernel="5.1.0")
  The __ASSUME_TIME64_SYSCALLS flag defined.

- Linux v5.1 and default minimal kernel version
  The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports
  clock_getres_time64 syscall.

- Linux v4.19 (no clock_getres_time64 support) with default minimal kernel
  version for contemporary glibc

  This kernel doesn't support clock_getres_time64 syscall, so the fallback
  to clock_getres is tested.

The above tests were performed with Y2038 redirection applied as well as
without (so the __TIMESIZE != 64 execution path is checked as well).

No regressions were observed.
2019-10-27 21:49:25 +01:00
..
alpha alpha: force old OSF1 syscalls for getegid, geteuid and getppid [BZ #24986] 2019-09-14 18:22:52 +02:00
arm Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
bsd Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
i386 Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
inet Remove obsolete, never-implemented XSI STREAMS declarations 2019-03-14 15:44:15 +01:00
mips Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
powerpc Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
sh Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
sysv/linux y2038: linux: Provide __clock_getres64 implementation 2019-10-27 21:49:25 +01:00
x86_64 Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
clock_gettime.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
clock_nanosleep.c time: Introduce function to check correctness of nanoseconds value 2019-10-27 21:49:25 +01:00
clock_settime.c time: Introduce function to check correctness of nanoseconds value 2019-10-27 21:49:25 +01:00
confstr.h
get_child_max.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
getlogin_r.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
getlogin.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
getpagesize.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
grantpt.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
ifreq.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
Implies
make-syscalls.sh Remove PREPARE_VERSION and PREPARE_VERSION_KNOW 2019-09-17 17:09:01 -03:00
Makefile Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
pt-fcntl.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
s-proto-cancel.S
s-proto.S
setxid.h
sockatmark.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
stime.c Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
syscall-template.S Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
syscall.S Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00
syscalls.list posix: Consolidate Linux fsync syscall 2017-05-18 18:06:47 -03:00
sysdep.h Prefer https to http for gnu.org and fsf.org URLs 2019-09-07 02:43:31 -07:00